


Concerning Flight

by trill_gutterbug



Category: Marvel Cinematic Universe, Thor (Movies)
Genre: Cunnilingus, F/M, Genderfluid Loki, In Which Trill Continues to Name Fics after Star Trek Episodes Because Why the Eff Not, Lady Loki, M/M, Post-Thor: Ragnarok (2017), Vaginal Sex
Language: English
Status: Completed
Published: 2018-01-31
Updated: 2018-03-06
Packaged: 2019-03-11 22:11:41
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,846
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13533576
Author URL: https://archiveofourown.org/users/trill_gutterbug/pseuds/trill_gutterbug
Summary: Loki, quite solid, jerks upright in a riot of blankets, emerging from an explosion of hair grown long over the past year of their journey to Earth. His eyes flash in the low light, teeth bared, and-- oh.“Oh,” says Thor. He pauses, surprised. His grin finishes forming. “Sister.”





	1. Chapter 1

There’s a strange shimmer when Thor opens the door to his rooms. He hesitates, one hand flat on the lock scanner, peering inside. The hair on his arms rises, a tingle of electricity crackling between his fingertips. The scanner sparks in sympathy. He pulls his hand back. Behind him, the corridor is empty, the lights dimmed for night. The ship is quiet, everyone but the bridge nightwatch gone to bed.

He takes a cautious step into the room. The air shimmers again, a gentle blur at the corner of his vision like a heat distortion, dissipating around him as he passes through the doorway. He realises that it’s a familiar sensation at the same moment he spies the lump in the middle of his bed. He relaxes.

His rooms are dim. The interior lights are off, but the ship’s violet thrusters glow through the windows. It’s more than enough to make out the mass of dark hair resting on his pillow.

“You could have told me you were back,” he says aloud, reaching to undo his tunic. He pulls apart the ties at his throat, then the ones at his wrists. “Heimdall didn’t say.”

The figure in his bed stirs, groaning.

Thor shucks his tunic over his head and tosses it on a chair. It’s a fine piece of clothing, soft blue and gold linen, donated anonymously after his ascension. “I assume your trip was a success, or I would have had to repel boarders or flee some kind of space monster by now, aye?”

No answer except another, lengthier groan.

Thor kicks out of his shoes (also donated) and undoes his belt. The breeches are his own, well worn and comfortable. He pulls open the button and then pauses, looking at his bed. “You _did_ succeed, didn't you?”

The answer comes muffled into the pillow. “Shut up, let me sleep.”

“You’re in _my_ bed, brother,” Thor complains, but he’s beginning to grin. It’s been a long and nerve-wracking week. He had only very slightly expected Loki to return at all. And come to think of it...

He leans over and pokes the centre of the lump, hard.

“Ow!” Loki, quite solid, jerks upright in a riot of blankets, emerging from an explosion of hair grown long over the past year of their journey to Earth. His eyes flash in the low light, teeth bared, and-- oh.

“Oh,” says Thor. He pauses, surprised. His grin finishes forming. “Sister.”

Loki narrows her eyes, which look sickly bright even in the dim room, bruised around with exhaustion. “Don’t,” she warns.

“What?” Thor knows his smile is veering sideways into saucy, but he can’t help it. “Is that not what you are?”

Loki glowers at him. She’s very pale, more than usual. For the first time, the thought occurs to Thor that perhaps her mission didn’t go very well at all, that she has dragged herself back to die in his arms (again) (maybe even for real this time). He sobers.

“...I suppose,” Loki says at last. Her voice is hoarse. “It’s just…”

She trails off, but Thor suddenly understands. The word sister has taken on a taint for them both. He reaches to brush back a handful of Loki’s thick black hair, touching his thumb to the corner of her ashy-pink mouth. “I’m glad you’re back,” he says. “Are you alright?”

The way her eyes narrow this time is downright scornful. “Am I ever not?”

Thor decides not to answer that. He straightens to finish undoing his pants. “Would you mind?” He makes a gesture. She glares up at him like she might just drop back down and go to sleep again in the middle of the bed, but finally she rolls over to give him room.

It’s cool under the covers, as if a living body had not just been nestled there, but that’s typical where Loki is concerned. It should have been obvious long ago, Thor has often thought, what Loki truly is. He says nothing about it now, only moves closer to his sister and reaches for her with a firm hand that doesn’t show any of the tentativeness he still sometimes feels near her, regardless of her form.

She is naked, which also surprises him. She goes stiff beneath his touch, skin chilled, muscles tight, then relaxes with what Thor thinks is a deliberate effort, breathing out deeply.

“I’m glad to see you,” Thor murmurs into the dark between them. “I’m glad you’re alright.”

She snorts softly, but Thor hears no scorn in it this time. Only weariness and a grudging fondness. Or so he likes to think.

“Go to sleep, brother,” she says.

He does.

~*~

He wakes when the room’s lights begin to brighten for dawn. The schedule approximates an Asgardian day, a kindness Thor considers equally a cruelty: the meaningless number of hours that a nonexistent planet once took to orbit a now-lonely star. But his body is accustomed to this specific interval of night, regardless of how much time he has spent anywhere in the galaxy _but_ Asgard, and he wakes slowly but surely to see the window reflecting not the passing field of stars, but the inside of his own rooms. Untidy, small, the only home he has.

Against his shoulder, his sister stirs in her sleep and tucks her face deeper into the curve of his chest. Thor looks down at her, taking in the soft angle of her jaw and the pale line of her throat, her long hair tangled in his beard.

Well. Perhaps not his _only_ home.

~*~

He lies quietly in bed beside her for a long time, until the light has come up all the way to a cheery mid-morning glow and he can hear the bustle of wakefulness throughout the ship. It’s relaxing, more rest than he’s gotten in weeks. He feels warm and tender all the way through.

He’s been humming softly to himself, an old dirge the work crew had been singing belowdecks yesterday. It’s gone around in his head ever since, the words and tune coming back to him bit by bit, unearthed from a century of forgetfulness.

“Would you stop,” Loki mumbles against his shoulder.

The soft rumble of the song trails off as Thor looks down at her. He hadn’t noticed her waking up. He’s feeling just content enough to be gracious.

“Sorry.”

He smooths his hand down her bare back and over the round of her flank. Her thigh is crooked up overtop his, a soft and intimate fact he’s been excruciatingly aware of for the past hour. His cock is hard, but he hasn’t been ungallant about it. Sometimes Loki takes poorly to Thor’s assumptions, so Thor has tried hard not to assume, no matter how much more often lately Loki has been demanding his attentions.

She squirms and he is made painfully aware also of her breasts, the heavy swell of them pressed into his side. He takes a quick breath, cock flexing. Without meaning to, his hand squeezes the curve of her ass.

Loki makes a noise equal parts unhappy and mocking. “Appalling behaviour, brother,” she says, but she moves against him again in a way that is clearly calculated. An invitation.

Thor takes it with a groan. He rolls onto his side toward her, slipping his hand beneath her thigh to draw it tighter against him, over his hip. It pulls her flush all along his body, her breasts pressed into his chest, her cunt--

She gasps as his cock pushes at her. It hurts him a little, her nest of coarse hair scratchy on his bare flesh, but the sting of it only gets him harder, grinding against her. He ducks his face into her throat and at the same time she slips her arm up around his neck, pulling him closer.

“Thor--” Her voice breaks when he pushes a hand down to touch her between the legs, where she’s already starting to get wet. His cock is stiff as an iron tool, ready to be put to use. He feels electricity in his hands and touches her with it, just a little. She moans, body seizing. He turns his face to find her mouth. She kisses him like she’s been waiting a century. He makes it rough, because he knows she likes to have her lips burnt with his beard and her tongue bitten. Her cunt wrings at his fingers when he eases them just inside. It’s been too long since he’s made love to a woman, felt that specific sensation, the slipperiness of her arousal, the heat of it. He doesn’t mean to be brash or presumptive, to take before she’s ready, but when he pushes his cock against her this time, and says her name with a helpless pleading note he hadn’t intended, she gasps, “Yes, alright, go ahead,” and he does.

She’s as tight and slick as he remembers-- and he has remembered it many times since the last. Usually hungrily, sometimes angrily, always longingly. When the head is inside, he puts his hand on the small of her back and draws her in slowly, letting her adjust to the stretch of it.

She clings to him and makes a noise like he’s killing her, a snarl between her teeth, her eyes shut tight, her head thrown back. He kisses her throat, pants against it, biting her so he won’t thrust forward too quickly. It takes so long to get in to the hilt, although it must only be seconds. It’s become blisteringly hot under the blankets, the blood rushing through him. He throws the covers off. This way he can see more of her, her pale thigh wrapped around his waist, the slope of her ribcage. He curves his hand around her breast, finds her nipple with his thumb and rubs it.

“Good?” he whispers, when what he really wants to know is if he can fuck her properly yet.

She cracks an eye open to give him an irritated look, because she knows what he means, but she nods.

It’s a strange angle, forcing him to go slower than he wants, but the tempering effect of it draws out the pleasure. Loki is just as affected, her nails digging at his back, her hips working a counterpoint to his. She finds his mouth again with her eyes shut, kisses him with increasing desperation until finally, toward the end, they’re only breathing hard against each other, tongues barely touching. She reaches between them and he can feel against his belly how she’s rubbing herself, bringing herself to the edge. It makes his head spin, his balls tighten. When she comes, he almost does too, the excruciating savagery of her squeezing cunt very nearly too much, but he clenches his teeth and holds off until her cries have turned to panting and her body is trembling against him fitfully.

“Loki,” he begs, holding still so he won’t embarrass himself. “Can I-- are you--”

They are more than capable of making babies together when Loki is in this form, a fact they learned with nearly disastrous results one lengthy and single-minded teenage summer. At the time, the forgiving arms of Asgard’s vast medical infrastructure had saved them both from the consequences of their unthinking actions, but now…

“Yes,” says Loki, who had devoted herself after that to a full understanding and mastering of her biology and the magical contingencies required to govern it. “Do it.”

He’s never heard two such welcome words. He rolls them over onto his knees, Loki on her back beneath him, one arm still hooked around his neck. He pushes her thigh up, opening her wider, and works himself deeper inside. She moans, shuddering, scratching him. Her other leg curls around his waist, cradling him in the sweaty, salt-smelling tangle of their bodies together.

He comes after a dozen hard thrusts, overwrought and overcome, growling into her hair, his teeth in her shoulder. When he’s done, he stays inside, shivering. Her hands on him are unusually tender, stroking the length of his back and sides, squeezing the nape of his neck, her lips on his damp temple. She gentles him down from the height of it, until finally he lifts his head to kiss her. She opens lazily for him, her mouth warm, the stroke of her tongue welcoming. She gives his softening, sensitive cock a squeeze with her cunt, the way she used to when they were younger to tease him and make him yelp.

But it’s been a while since she last had the opportunity, and he is no longer a young man short on experience and long on only one thing. He grins and pushes back at her, his cock starting to stiffen again.

“Ugh,” she groans. “More?”

He pushes up on one braced hand to look down at her. She doesn’t flush pink with pleasure the way most people he’s bedded do, but she gets that same glassy pleased look in her eye and that smug slant to her smile. Her face is a little sharper in this form than the other, the line of nose and chin more delicate, but to his familiar eye her expressions are all the same, the touch of her hand and the way she moves beneath him. She runs her palm up his cheek, tracing the edge of his patch, and scratches her nails along his scalp. It feels so good, nearly as good as the sharp hungry throb of his cock in her, that he shuts his eye and drops his forehead to her collarbone so she can keep doing it. He has kept his hair cut short for the past year, as much a symbolic gesture of the new state of their kingdom and how he intends to govern it as a matter of convenience, so it’s not the same as when Loki would braid his hair when they were children, combing and petting it for as long as Thor could bear to sit still. It’s better.

She sighs beneath him, a long deep breath that settles her into the mattress and him into her in equal measure. They are sticky everywhere they touch, still too hot. Thor could nearly fall back asleep on top of her, although the interested state of his cock suggests other things he could do on top of her, but before he can decide one way or the other, there is a knock at the door.

He lifts his head, frowning. “What?” he shouts over his shoulder.

“You’re needed on the bridge, Your Majesty,” Valkyrie shouts back. “Bit of a situation!”

Thor snaps his head around to look at Loki. She shrugs, one hand still curled in the short hair at the back of his neck. She looks a little too innocent.

Thor groans, partly resigned and partly longing, because now that he has to withdraw from her, his body has decided that is exactly the opposite of what it wants. He pulls out carefully, wetly, wincing, and draws up a handful of sheet to wipe himself. Loki smirks at him, her eyes tracing appreciatively down the length of his body and back up. Thor can’t help himself. He flexes a little for her, grinning. She rolls her eyes and pushes him backwards with one foot until he has to climb off the bed or fall.

“I’m coming!” he grumbles, when Valkyrie bangs on the door again. He grabs his pants from the floor, cringing when he has to bend his still-hard, still-damp cock under the waistband.

Loki crooks a finger. “Here, let me fix that for you.”

“No, I don’t think so.” Thor shudders, remembering the one time he had been foolish enough to take his then-brother up on that offer, and been zapped with a blast of cold from Loki’s hand so severe that his erection had indeed been cured. For days.

Loki chuckles and rolls over to nestle back into the mess of blankets. She looks, in that moment, so utterly beguiling, her back long and strong, her buttocks smooth, her thighs parted and wet, such a beautiful and luscious and moreover familiar symbol of comfort and contentment, that Thor has to pause with his tunic balled in his fists and force himself not to crawl back into bed with her and let the ship fend for itself.

He has obligations, damnit. Responsibilities.

“Go away already,” Loki says, muffled into the pillow. “Stop staring at me.”

“You love it,” Thor mutters, but he heads for the door.

It opens just as Valkyrie is raising her fist to pound on it again.

“Finally,” she says. She looks over his shoulder into his room, frowning. “Who were you talking to?”

Thor half turns, mouth open, hesitating, but… His bed is empty-- or so it appears. There’s a dip in the mattress just where he knows to look for one. He smiles and steps out into the hallway.

“Myself,” he says.


	2. Chapter 2

**Notes for the Chapter:**

> Apparently I have more smutty things to say about this situation.

When they were young, Thor had not been good at lovemaking. Not at first. He had been ferociously enthusiastic, exuberant, voracious even, but not good. 

Loki had told him as much immediately, as soon as they had lain together the first time. Before that first time was even over, in fact. Loki had ended it in media res with some choice words and a judicious kick and Thor had been ousted from his brother's bedchamber with clothes in hand, bewildered and offended, the door slamming on his bare ass. 

What followed was a tumultuous period of experimentation and education, which Thor had taken to with the driven grimness of a boy insulted and an ego smarted. He sought out a thorough series of lessons in carnal activities from as comprehensive a demography as possible. He had learned, and practiced, and come back to Loki with a proposition for a rematch. Loki had taken him up on it, grudgingly, suspiciously, and… Well. Thor considered it a success. Loki's jealous rage after the fact (and Thor’s subsequent injuries to both body and heart) had been more than evidence of that. 

But Loki's jealousy had only kept him from Thor’s bed briefly, and thereafter Thor received all the remedial experience he could possibly have wanted. It was that same year that Loki, perhaps inspired by Thor’s own forays into the realm of the fairer sex, or slyly seeking to divert them, learned to change his form. He had always, since they were young children, been able to become small animals and fairytale creatures, but this was the first time he became Thor’s sister. 

The change was remarkably little. Loki, it turned out, was as she had always been, though perhaps more relaxed in her new form in some way that Thor could see but not name. More sure of herself and less calculated in the way she moved, the surety with which she demanded his attention. 

He gave it to her without question or hesitation, greedy for her in any shape, in any way. He learned all over again how to play the instrument of a woman's body, how to use his fingers and his cock and his mouth to make her feel good. The more sore he was by the end, the more marked with scratches and bruises and bites, the more accomplished he felt. It was a challenge the way the battlefield rarely was anymore, for all he loved it. He craved besting enemies in battle, smashing heads and shattering bones with Mjolnir in hand and his friends at his back, but nearly as much as that, he craved having his head between Loki's legs and her hands in his hair. 

He dreamed about it, he hungered for it, he thought of nothing else for weeks. He begged her for the pleasure of it, and she would not deny him for longer than she herself could stand it. He came to her rooms after dark, when everyone but the guards slept; they went out riding together and stayed away for hours; he would find her in the stables and push her back into the darkest corner of the farthest stall and go to his knees in the straw. 

She was a woman for nearly that whole year, while they starved for each other. They thought they were subtle, but Thor realised later that of course they were not. They were children, self-obsessed and sure that the world revolved around them at the same time they were sure their actions made no difference to anyone. They were almost caught more times than Thor could count, although Loki became adept at hiding them when necessary. 

Once, in a hallway not nearly as disused as Thor insisted it was, he had pressed Loki into an alcove and kissed her fervently until she went soft against him and stood on her toes to put her arms around his neck, then he had slid down her body onto the floor and gotten under her skirts right there in the open. He lifted her thigh over his shoulder to open a space for himself, and ate at her with such ardour that she tore her own dress clawing at him. When a servant came along the corridor, she barely managed to throw a glamour over them both in time to avoid detection. 

Or so she had said, at least. Thor thought later that it was not a coincidence that his mother called him that night to see her, and delivered a horrifyingly blunt and specific lecture on the fair and safe treatment of women, and his obligations to King and crown. 

It had not slowed them in the least. Nothing had, except time and familiarity, and Loki's increasing resentment of Thor and Thor’s increasing obliviousness to it. 

But now… Now that so many years have passed and they have found one another again with hurts laid bare and intentions made, if not clear, then less important by things greater than either of them, they seem to be revisiting those early days with a vengeance. 

When Thor returns from the bridge (as Valkyrie had said, a bit of a situation, but even more surprisingly, not Loki’s fault), he once again steps through that odd shimmer in his doorway. He suspects it would give a warning or a painful zap to anyone but him who tried to cross it. 

Loki is still in his bed, still a woman, still sleeping. Her mission must have been exhausting indeed, to deplete her this thoroughly. The blankets are tossed at the foot of the bed, her naked body bare. The room is cool, but that has never bothered her. She’s lying on her belly, face buried in the pillow, one leg drawn up just enough that Thor can see… 

He shuts the door quickly. There's no one around, but he feels clandestine and protective all the same. He crosses the room quietly so as not to wake her. 

Her legs are long, her thighs strong with lean muscle, the curve of her ass thick as a haunch of meat he might sink his teeth into at the dinner table. She is not hairless, as Thor learned has become the Midgardian fashion. He had been shocked, and then eventually titillated by the novelty, to find Jane smooth as a river rock when they had undressed together for the first time. He had spent a long time running his hands up and down her curiously soft calves and thighs, her cunt (although she had frowned when he called it that) naked beneath his touch. 

There is none of that beguiling coquettishness with Loki; she is as she was made, raw and natural to Thor’s eye, the smell of her still thick with their earlier lovemaking, the fold of flesh where her hip meets her belly as delicious to him as the dimples behind her knees and the calluses on her hands. 

He sits on the edge of the bed and tilts his head to take her in fully, the way he hadn't had the chance to last night or earlier this morning. His cock stirs, but he ignores it. It has been giving him trouble all day, ever since he left his sister in bed, tormenting him with recollections of her breasts under his palms, his name on her tongue. Too many people have accused him of distraction today, too many foolish fumbles have been made, for him to reward himself now. But there are other things he might do, and if he wishes to call them a reward for his sister and not himself… Well, they would both know the lie. 

He touches the back of Loki's thigh, runs his hand up it slowly to the swell of her ass, squeezing gently. He doesn't want to wake her, not all the way, but he wants her to know he's there. She stirs, just a little, her hand curling on the pillow next to her head. 

“Just me,” says Thor. 

He slides his thumb into the damp space at the apex of her thighs, where he can see a curl of damp hair and a sliver of delicate pink. He tugs gently to open it. His cock jerks sharply again. His mouth has already begun to water. She's still wet from that morning, her own arousal mixed with his seed. Surprising, since she is usually fastidious about cleanliness, but Thor is glad of it. He has always liked evidence of where he has been and what he's done. Likes marking and being marked. 

He pushes his thumb gently into her, where she is slick and warm. Her hips flex against the bed, shifting. “What do you think you’re doing?” she mumbles.

“Don't mind me,” Thor says, instead of answering. He withdraws his thumb and pushes her thighs open, easing the right one up the bed so she is spread open for him. He has to stop at the sight and groan, his whole body flushing hot. Her cunt is slick and tender and bare, the smell of it rising warm, the insides of her thighs begging to be bruised and scratched with his beard. He slides down the bed onto his belly and ducks his head between her legs. 

If she hadn't been awake before, she is after the first lick. It's a deep one, tasting and hungry, from one end of her slit to the other. He feels her jerk, muscles clenching, when he touches her clit. It might still be sensitive from earlier, the way his cock is. He hopes so. 

He turns his face to get at her better. It's not an easy angle, but it is a rewarding one. He slips his tongue up inside her and tastes himself. She gasps when he does that, her hips lifting from the bed and pushing back at him. He slides his hand beneath her belly to hold her there, against his face. It opens her up beautifully. 

“Thor…” she says. “Oh, you  _ bastard _ \--” and then breaks off into a choked whine when he finds her clit again and licks it. He stays there for a while, rubbing with the flat of his tongue and then, when it is slick and fat and hard in his mouth, with the point. Her legs shake on either side of his head, her belly tight under his hand. She pushes back on him in a helpless rhythmic way that means he's doing well. 

When she's getting close, he brings up his other hand and slides two fingers into her, pressing inside to find the place she likes to be stroked with fingers and cock, that sometimes has made her soak him with ecstatic pleasure when he's fucked her just right, and he doesn't stop until she comes with a bitten-off scream into the pillow, her thighs snapping shut around his head, her cunt seizing around his working fingers. He sucks her until she pushes him away, then goes back in for another lick, payment for the way she tried to tease his cock that morning. 

He slaps her on the buttocks when he sits up, because he knows she likes and despises such treatment in equal measure. She doesn't even turn to chastise him. She only pants and shivers against the bed, gasping for breath. 

Thor reaches at last for his belt. He makes sure she hears him open the buckle.

She shudders when he lifts her by the hips. She moves with him, arching her back so there is a clear path. He enters her as slowly as he can manage, groaning at it, how she's fluttering and wet inside. He won't last long and he doesn't think she'll mind. 

She looks at him over her shoulder. Still pale, still free of sweat, but her hair is a beautiful snarled mess and her mouth is wet and red from her own teeth when she says, “Fuck me, brother.”

He obeys, savagely, thoroughly, and comes soon deep inside her, one hand tight on her hip and the other curled around hers, fingers tangled together. 

**Notes for the Chapter:**

> I may continue this as the spirit moves me, but for now... It's just gratuitous smut lol.


End file.
